DPI systems are used by many organisations as firewalls but they can also collect information. Photograph: AAP

Controversial new technology capable of collecting and storing emails and other information sent via computer in real time will be rolled out by the Australian Federal Police next year.

The agency plans to trial "deep packet inspection" (DPI) technology in February before a full rollout in April.

DPI systems are used by many organisations as firewalls but they can also collect information such as email subject headers and message content.

America's National Security Agency has used DPI for internet surveillance because it can collect data in real time and capture it at 10 gigabits per second – two features requested in the AFP tender documents.

The documents also show the system must be able to "extract and store metadata", or the raw information behind messages such as phone numbers, email addresses and the dates, times, locations and duration of calls and emails.

Metadata hit the headlines last week when documents leaked by US whistleblower Edward Snowden said Australia's Defence Signals Directorate had told its overseas counterparts that it could share with them "bulk, unselected, unminimised metadata as long as there is no intent to target an Australian national".

The AFP insists it is to be used as "a system tool" within the organisation.

"This technology is common among commercial and government IT systems throughout the world," a spokesman said on Tuesday.

It will not be connected to any external telecommunications or other IT networks and is not associated with data retention in Australian telecommunications networks.

The US-based Centre for Democracy and Technology describes the technology as "really no different than postal employees opening envelopes and reading letters inside".

Tenders for the new system, which comes with a three-year confidentiality clause, close later in December.

Prime Minister Tony Abbott said last week he was confident that Australia's agencies acted within the law and there were proper privacy safeguards in place.